Controlled conveying and feeding of abrasives



pri l2, 1932.

JjA. HEALY 1,853,611

CONTROLLED CONVEYING AND FEEDING OF ABRASIVES l Filed April 5, 1930 Patented Apr. 12, 1932 n UNET ,JOSEPH ALFRED HEALY, OF

BARRE, VERMONT GONTROLLED CONVEYING AND FEEDING OF A-BRASIVES Application ledApril 5, 1930.. Serial No. 442,005.

In the sawing or dressing of stone and the like with abrasives, the conveyance and feed of the abrasive, as the important service element inthe operation, from its place of stor- V dressing instruinentality, as a `gang saw or polishing wheel, has been more orless liaphazard with the result that there was'no real control of the abrasive according to the requirements of the particu- ,o larpiece of work being performed.

Frequently, the matter of abrasive feed is left to thevjudgment of the particular workman who simply shovels the abrasivev onto the work whenever and insuch-quantities as he considers necessary. Y

Where automatic feed has been attempted, and particularly in the case of the stone saw, an elaborate system of conveyors and uniform cutting action. Where this type of abrasive has been pumped to a saw,for eX- ample, it was necessaryvto pumptheabrasive into an overhead ltank vfrom.fwhich itk flowed onto a perforated platform and wasV spread onto the top of the block being worked upon. This made for non-uniformity of feed, and usually an under feed of abrasive, due to the fact that the Vabrasive could not be pumped into the/,tank without carrying along with it a considerable quantity of water, mud, and cuttings. y

Where chilled lshot is used as an abrasive with water as in the sawing or dressing of granite 'or other stone, several factorsare involved, all havinga mutual bearing upon one another and all individuallyv and collectively affecting the ultimate result. For example, the material being operated upon, 59 the machine being used, and particularlythe Vhas characterized such elevators have been necessary for conveying however, does not make a` y `ity using an abrasive, as of obtaining a uniform feed, and hence a.

blade and shape and spacement of the teeth if a saw, the abrasive and its application, and the water and its control are all contrib uting factors.v

As heretofore indicated, with all prior methods used inthe industry, sorfar as I am aware, the lack' of control o-f the water and abrasive has been the principal cause ofthe non-uniformity of feed and fhence non-uniformity in dressing or cutting action which 60 prior art practices. Accordingly, the concept underlying, my present invention is that ofso conveying and feeding the abrasive as positively and i Vaccurately to'permit of its control at'v allu times and under all conditions of use, ao-l cording to the particular material being operated uponand the particular type 'of operating instrumentalit v For the purposes of this application I shall discuss my invention in its adaptation to a gang saw, although it ywill be understood that this treatment is purely illustrative and in no way limiting, and that the principles of my invention may be applied to any 'I5 saw wherein thel abrasive is fed to the saw bla-de or blades whileV the saw is` at work, or to any grinding or dressing instrumentalfor example, a polishing wheel.

Considering the 'gang saw as typical of the roblems involved, however, it will be evident that an adequate and uniform feed of the abrasiveto the several'saw blades must be maintained at all times and in all positions of the blades, and that unless such feed is adequate, the cutting action will not be uniform. v Y Y With these considerations inl mind, I have approached the problem from the point of 90 view of positively controlling the conveyance and feed ofthe abrasiveto the saw or other instrumentality, such .positive control applying not onlyto the admission ofthe'abra sive and water to the distributing member but to the discharge thereofas well as onto the work according to the particular'operating conditions vpreva'li'ng. In carrying out myA invention, I depart sharply from prior practicein my use of a 1 simple rotary rotating distributing member from which the abrasive is fed to the saw orother instrumentality. Such member may take the form of a drum, tank or similar receptacle disposed above the work for movement about a fixed axis relative thereto.

As is well known in the art, chilled shot, and sand, carborundum or like granular abrasives, with or without water, will not flow freely in a stationary receptacle, but on the contrary will pile up at the intake and choke the receptacle, but this deiicien-cy is instantly overcome when the. receptacle is rotated or oscillated about its axis in which event the abrasive seeks its own level as would waiter. Such movement may be a movement or the drum may be both rotated and oscillate'd relative to the work.

My in'venti'ontakes advantage of this well known principle', and Vaccordingly I have provided for either rotating or oscillating, or both, the distributing receptacle over' the work. The rotary motion prevents choking up of the drum with the abrasive and the oscillating motion insures adequate distribution of the abrasive to all point-s of the saw blade or blades.

The rabrasive and water is admitted under controlled conditions into one end of the rotating receptacle, and is discharged onto the work through a slot or slots or a row or series of rows of perforations formed Vin theycircumference of the drum intermediateV of the ends thereof, the excess abrasivev not discharged through said openings being carried oli1 through a suitable overflow opening at the opposite end of the drum. y

The level of the abrasive and water in the drum is controlled by the size of the overflow opening, and the quantity of abrasive and water discha'r, ,"ingv onto'l the saw or other instrumentality iscontrolled by the size and number of discharge perforations. If addi tional water for the purpose of cooling the blade orV blades is' necessary, this may be supplied by means of an independent sprinkler with regulating valve.

By regulating the size, spac'ement and number of discharge openings, the arc of swing if the receptacle is oscillated as well as' rotated and rate of rotation, I am enabled to secure a. feed of the abrasive to the saw or other instrumentality which is uniform at all points in the stroke of the saw and to all ofthe sawV blades, if a gang saw.

My' improvements are applicable to saws or other grinding, polishing, or dressing machines of standard type without modification orpreorganization of structure.

In the drawing l A The single figure is an elevation', partly in section, of a lform of apparatusv which I have found entirely satisfactory for the practice of mv invention.

The chilled shot or other abrasive and the water is fed in any suitable manner into the elbow l of a distributing receptacle 2 which is supported above the work for either rotary or rotary and oscillatory motion, relative thereto.

Such receptacle may be a cylindrical or otherwise shaped body, perforated or' other- Wise ooened intermediate of its ends, to provide one or more abrasive discharge openings 3. The end closures or heads al of the receptacle' may be mounted in roller bearings 5 at the lower ends of a pair of rocker arms 6 on a shaft which if the receptacle is to oscillate as well as rotate may conveniently be a rock shaft 7. Y The roch shaft 7 be" rocked in any suitable manner as by the actuatingm'embers 8.

In addition to the rocking motion imparted to it from the rock shaft' 7, the drum may be rotated from any suitable power source and by any suitable motion transmitting' connections. As here shown, I have provided a simple sprocket and cha-in drive for the drum, the sprocket 9 being fast on the drum and the sprocket l being carried by a sleeve ll running loose on the shaft 7 and driven by any suitable belt not shown The sprocket chain is indicated at l2.

The hub of sprocket 9 may serve as an' endthrust bearing for one end ofthe drum, and end thrust at the' opposite end' may be taken care of as at 13.

For some purposes it may c to rock the drum, in which event the rocker arms 6 will fit loosely on the rock shaft T.

Similarly, it may be desirablefor some purposes to incline the drum' relative to the work.y and this may be taken care of in any obvious manner. For most purposes, however, ahori` Z'ont'ally disposed drum is entirely satisfactory. v

'In' use, the shot and water, or other abrasive, is fed continuously into' the' intake end of the drum gs' at l and such as is" not discharged onto' the saw blades through the perf-orations 3 escapes through the overflow opening-V14E at the opposite end of the drum into the hopper 15 from which be' unnecessary it is returned in any suitable manner to the intake l'. Preferably, although vnot necessarily, the overflow 14 is in the form of a plurality of spaced openings in the adjacent head l of the drum. v

The rotation ot' the drum insures adequate distribution of the abrasive without clicking or piling up throughout the entire length thereof and the perforations 3 permit controlled discharge of the abrasive and water onto the saw blade or blades.

The oscillatory motion of the c rum if the drum is also oscillatel insures adequate' distribution of the abrasive to all points in the stroke of the saw blade or blades Without anyv of the abrasive l soi tendency to over-feed at the center and underfeed at the ends of thestroke.

Where used with a gang saw, there will preferably be one row of perforations 3 for each blade of the saw, and these perforations may be staggered relative to each other in parallel rows as shown, although such arrangement is optional.

The abrasive level may be any desired level but must be deep enough to keep the discharge perforations rIhe overflow at 14 maintains the level constant or substantially constant, regardless of variations in rate of feed or discharge, and the rotation of the drum prevents choking up. Moreover, the shot is in a condition of continual agitation in the water and hence is washed and kept clean thereby.

Thus by the use of a rotating abrasive receptacle with abrasive intake at one end, overflow at the opposite end, and abrasive discharge to the work intermediate of said ends, I secure a control of the abrasive and water never before attained in the art. Moreover, I avoid the necessity for any elaborate and complicated systems of conveying and feed ing, the drum itself being at once both a conveyor and a feeder.

As before indicated, some uses may not require that the drum be oscillated, and accordingly this feature is to be regarded as optional, depending upon the particularinstallation contemplated.

While the adaptation for a gang saw is typical the invention is in no way limited to such use alone, being in fact usable for the conveying and feeding under yconditions of positive control of any abrasive to any cutting, sawing, polishing or grinding machine using abrasive.

It will also be understood that instead of a row or rows of perforations for the discharge of the abrasive onto the work, I may discharge through a slot or slots, or any other equivalent discharge opening or openings formed in the drum. Y

Similarly, whether perforations or slots are employed, these may extend wholly .or

.terial supplied 3 covered with abrasive.

er' capacity which the receptacle is to the tool, means for rotating the receptacle yto level the abrasive material supplied therealso having overiow opening means of relal v tively large size such that any abrasive mato the receptacle in excess o that discharged through the delivery opening or openings nds a Vready exit from the receptacle, whereby the'level of the abrasive material within the receptacle and thereby the feed of the abrasive material to the tool is adapted to be maintained uniform.

2. Apparatus as set forth in claim 1 in which the overflow opening means is of greatthan the inlet opening means whereby abrasive material cannot be supplied to the receptacle in such quantities as` to raise theV predetermined abrasive level within the receptacle.

3. Apparatus which the receptacle is in the form z'ontally disposed cylinder having the charge opening or openings in the side thereof a horiv of and the inlet and overflow opening means in the endsl thereof, respectively.

4. Apparatus as set forth in claim 1 in which the receptacle is mounted for movement bodily to different operative relative to the tool.

5. Apparatus asset forth in claim 1 in pivotally suspende for swinging. movement bodily to different operative positions relative to the tool.

In testimony whereof I aiix my signature.

Y J ALFRED HEALY.

only partly around the circumference of the drum and may be staggered with respect to each other, or may be extended spirally or otherwise arranged, as circumstances require. These, and all such variations in method and apparatus are to be regarded as within the spirit and scope of my invention, ned by the appended claims. l

What I therefore claim and desire to secure by Letters Patent is:

asde-Y 1. Apparatus for feeding abrasive material Y to a tool comprising a receptacle adapted to be mounted above the tool and into which the abrasive material is adapted to be introduced, said receptacle havin therein through whic the abrasive material is adapted to be delivered from the receptacle one or more apertures y as set forth in claim 1V inV dispositions d 10ol 

